Co­lum­bus and his men may have in­tro­duced syph­i­lis in­to Ren­ais­sance Eu­rope af­ter con­tract­ing it dur­ing their voy­age
to the New World, a study sug­gests. But sci­en­tists say it will take fur­ther re­search to so­lid­i­fy the con­clu­sion.

The
Landing of Columbus by John Vanderlyn, placed in 1847 in the U.S.
Capitol rotunda.

Re­search­ers in­volved in the study
called it the most com­pre­hen­sive ge­net­ic anal­y­sis yet done com­par­ing tre­po­nemes—mem­bers of the bac­te­ri­al family that causes syph­i­lis and re­lat­ed dis­eases such as yaws.

De­bate has raged for cen­turies over wheth­er Co­lum­bus’ voy­ages were re­spon­si­ble for in­tro­duc­ing Eu­rope to syph­i­lis, a com­mon ve­ne­real dis­ease. At one time a ma­jor kill­er, un­treated syph­i­lis can lead to com­plica­t­ions in­clud­ing men­tal ill­ness and heart dam­age.

The first
known ep­i­dem­ic on rec­ord of the dis­ease then known as “evil
pocks” oc­curred in 1495 in Eu­rope. That was two years after Co­lum­bus
re­turned from his first New World vo­y­age.

Kris­tin Harp­er of Em­o­ry Un­ivers­ity in At­lan­ta, Ga. and col­leagues used phyloge­net­ics, the study of ev­o­lu­tion­ary re­lat­edness be­tween or­gan­isms, to ex­am­ine 26 ge­o­graph­ic­ally dis­par­ate strains of tre­po­nemes. The ve­ne­real syph­i­lis-causing strains
ori­g­i­nat­ed most re­cent­ly, and their clos­est rel­a­tives were strains col­lect­ed in South Amer­i­ca that cause yaws, she said.

“That sup­ports the hy­poth­e­sis that syph­i­lis—or some pro­gen­i­tor—came from the New World,” she re­marked. In re­cent years, re­search­ers said, most of the ev­i­dence bear­ing on the de­bate has come from bones of past civ­il­iz­a­tions, which can yield clues be­cause chron­ic syph­i­lis causes skele­tal dam­age. But this anal­y­sis is of­ten in­con­clu­sive, partly be­cause of prob­lems dat­ing the bones, ac­cord­ing to sci­en­tists.

The new study in­di­cat­ed yaws is an an­cient in­fec­tion in hu­mans, while ve­ne­real syph­i­lis arose
more re­cent­ly, Harp­er said. The vari­ants her team an­a­lyzed in­clud­ed two never-before-sequenced strains of yaws from iso­lat­ed in­hab­i­tants of Guyana’s in­te­ri­or.

But in a com­men­tary pub­lished on­line in the jour­nal with the stu­dy, some re­search­ers ar­gue the case for the Co­lum­bi­an ori­gins of syph­i­lis re­mains far from closed. Harp­er’s study had “limita­t­ions,” some of which the au­thors ac­knowl­edged, wrote the com­men­ta­tors, Shei­la Luke­hart of the Un­ivers­ity of Wash­ing­ton, Se­at­tle, and col­leagues. Luke­hart ar­gued that the bac­te­ri­al family tree that Harp­er’s team in­ferred from the ge­net­ic ev­i­dence is­n’t as clear as the au­thors claimed, and that some of the loca­t­ions of the bac­te­ri­al genomes used for com­par­i­son weren’t the best choices. Fur­ther stud­ies may yield great­er clar­ity, they added.

“Syphilis was a ma­jor kill­er in Eu­rope dur­ing the Ren­ais­sance,” said skele­tal bi­ol­o­gist George Arme­la­gos, a co-author of the stu­dy. “Un­der­stand­ing its ev­o­lu­tion is im­por­tant not just for bi­ol­o­gy, but for un­der­stand­ing so­cial and po­lit­i­cal his­to­ry. It could be ar­gued that syph­i­lis is one of the im­por­tant early ex­am­ples of glob­al­iz­a­tion and dis­ease, and glob­al­iz­a­tion re­mains an im­por­tant fac­tor in emerg­ing dis­eases.”

Columbus and his men may have introduced syphilis into Renaissance Europe after contracting it during their voyages in the New World, a study suggests. But scientists say it will take further research to solidify the conclusion.
The researchers described the work as the most comprehensive genetic analysis yet done comparing treponemes—members of the bacterial family that causes syphilis and related diseases such as yaws. The findings are published Jan. 15 in the research journal PLoS Neglected Tropical Diseases.
Debate has raged for centuries over whether Columbus’ voyages were responsible for introducing Europe to syphilis, a common venereal disease. At one time a major killer, untreated syphilis can lead to complications including mental illness and heart damage. The first recorded epidemic in Europe occurred in 1495.
Kristin Harper of Emory University in Atlanta, Ga. and colleagues used phylogenetics, the study of evolutionary relatedness between organisms, to examine 26 geographically disparate strains of treponemes. The venereal syphilis-causing strains originated most recently, and their closest relatives were strains collected in South America that cause yaws, she said.
“That supports the hypothesis that syphilis—or some progenitor—came from the New World,” she remarked. In recent years, researchers said, most of the evidence bearing on the debate has come from bones of past civilizations, which can yield clues because chronic syphilis causes skeletal damage. But this analysis is often inconclusive, partly because of problems dating the bones, according to scientists.
The new study indicated yaws is an ancient infection in humans while venereal syphilis arose relatively recently, Harper said. The many different variants her team analyzed included two never-before-sequenced strains of yaws from isolated inhabitants of Guyana’s interior.
But in a commentary published online in the journal with the study, some researchers argue the case for the Columbian origins of syphilis remains far from closed. Harper’s study had “limitations,” some of which the authors acknowledged, wrote the commentators, Sheila Lukehart of the University of Washington, Seattle, and colleagues. Lukehart argued that the bacterial family tree that Harper’s team inferred from the genetic evidence isn’t as clear as the authors claimed, and that some of the locations of the bacterial genomes used for comparison weren’t the best choices. Further studies may yield greater clarity, they added.
“Syphilis was a major killer in Europe during the Renaissance,” said skeletal biologist George Armelagos, a co-author of the study. “Understanding its evolution is important not just for biology, but for understanding social and political history. It could be argued that syphilis is one of the important early examples of globalization and disease, and globalization remains an important factor in emerging diseases.”